I skipped some bits of the video so probably missed this, but: in the beginning he mentioned no spark or glow plugs and said “similar to a diesel”, but in the end that didn’t work and he had to resort to a glow plug.

Did he mention what fuel he was using for the compression-only attempts? If not actual diesel, it seems like he would have had to use ether or something like that.

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vessenes 2 minutes ago | parent | next [-]

https://modelenginenews.org/techniques/minid.html Mentions that this engine needs a spring start and 50% ether and it runs up to 40k rpm(!) seems like it’s finicky, which makes sense given its size

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RossBencina 5 hours ago | parent | prev | next [-]

It was a mixture of ether, castor oil, and something else. He theorised that the ether was boiling off in the tank before it made it to the engine.

	▲	antonvs 4 hours ago \| parent [-]
		Ah thanks - I was imagining that perhaps the engine didn’t have high enough compression to achieve ignition.

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Frenchgeek 5 hours ago | parent | prev [-]

He did: It was just warm enough for the ether in the mix to evaporate long before it reached the engine, so it couldn't run.